Abstract
The diarylheptanoid 7-(4′-hydroxy-3′-methoxyphenyl)-1-phenylhept-4-en-3-one (HMP) is a naturally occurring phytochemical found in lesser galangal (Alpinia officinarum). In the present study, we have demonstrated the anti-inflammatory properties of this compound on mouse macrophage cell line (RAW 264.7) and human peripheral blood mononuclear cells (PBMCs) in vitro. Treatment of RAW 264.7 cells with HMP (6.25–25 μM) significantly inhibited lipopolysaccharide (LPS)-stimulated nitric oxide (NO) production. This compound also inhibited the release of LPS-induced proinflammatory cytokines interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) from human PB-MCs in vitro. In addition, Western blotting and reverse transcription-polymerase chain reaction analysis demonstrated that HMP decreased LPS-induced inducible nitric-oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) protein and mRNA expression in RAW 264.7 cells. Furthermore, HMP treatment also reduced nuclear factor-κB (NF-κB) DNA binding induced by LPS in RAW 264.7 cells. To elucidate the molecular mechanism for inhibition of proinflammatory mediators by HMP (25 μM), we have studied the effect of HMP on LPS-induced p38 and p44/42 mitogen-activated protein kinase (MAPK). We observed that the phosphorylation of p44/42 MAPK in LPS-stimulated RAW 264.7 cells was markedly inhibited by HMP, whereas activation of p38 MAPK was not affected. These results suggested that HMP from lesser galangal suppressed the LPS-induced production of NO, IL-1β, and TNF-α and expression of iNOS and COX-2 gene expression by inhibiting NF-κB activation and phosphorylation of p44/42 MAPK.
Footnotes
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This work was supported by New Jersey Agricultural Experiment Station's Hatch Project (Cook College, Rutgers, The State University of New Jersey).
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Article, publication date, and citation information can be found at http://jpet.aspetjournals.org.
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DOI: 10.1124/jpet.103.049171.
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ABBREVIATIONS: NO, nitric oxide; IL, interleukin; IFN, interferon, TNF-α, tumor necrosis factor-α; NF-κB, nuclear factor-κB; COX-2, cyclooxygenase-2; NOS, nitric-oxide synthase; iNOS, inducible nitric-oxide synthase; HMP, 7-(4′-hydroxy-3′-methoxyphenyl)-1-phenylhept-4-en-3-one; LPS, lipopolysaccharide; PBMC, peripheral blood mononuclear cell; MAPK, mitogen-activated protein kinase; DMEM, Dulbecco's modified Eagle's medium; FBS, fetal bovine serum; MTT, 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl tetrazolium bromide; ELISA, enzyme-linked immunosorbent assay; RT-PCR, reverse transcription-polymerase chain reaction; PBS, phosphate-buffered saline; PMSF, phenylmethylsulfonyl fluoride; PCR, polymerase chain reaction; EMSA, electrophoretic mobility shift assay; DTT, dithiothreitol; bp, base pair(s); IκB, inhibitory κB; SB203580, (4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)-1H-imidazole); PD98059, (2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one).
- Received January 13, 2003.
- Accepted March 3, 2003.
- The American Society for Pharmacology and Experimental Therapeutics
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